Device and method for the production of rove by means of a pneumatic spinning process

ABSTRACT

The invention relates to a slubbing machine, the use of a twist application means, and a method for the manufacture of a roving yarn ( 9 ). The roving yarn ( 9 ) is manufactured according to the invention from a fibre assembly ( 3 ), which undergoes a true twist application (rotation) by means of one or more air flows.

The present invention relates to a slubbing machine for the manufactureof a roving yarn to a fibre assembly, as well as the use of twistinsertion means, which operates according to an air spinning process, amethod for the manufacture of a roving yarn, as well as a drawingframe-slubbing machine combination in accordance with the generic partof the patent claims 1, 2, 10, 14 and 18.

Such devices are known in the textile technology. To the slubbingmachines according to the present invention belong in particular the socalled speed frame. The speed frame serve to manufacture roving yarn orthe manufacture of what is referred to as a slubbing or roving. Theroving yarn serves as the basis for the spinning process, i.e. for thespinning of fibres to a fibre yarn, for example on a ring-spinningmachine. The fibre bands or slubbings coming from the preliminaryprocess (carding room) are, as a rule, first doubled with the aid ofdrafting devices and deposited in cans. The sliver which is produced bythis is then presented to the slubbing machines for further processing.In these slubbing machines the sliver is, as rule, first drawn in itsown drafting device and then slightly twisted by the application of asuitable twist before the original fibre assembly is wound up as aroving yarn on a supply bobbin.

The roving yarn derived in this way (also referred to as fibre slubbing,flyer slubbing, or generally slubbing) usually serves as a presentationmaterial for ring-spinning machines. The slubbing machine usuallycontains its own drafting device, in most cases a double apron draftingdevice. After being drawn through the drafting device of the slubbingmachine, the fibre assembly undergoes a slight twist (referred to as aprotective twist), in order for the slubbing produced by this to exhibita certain strength so that it can be wound on a bobbin and will notdisintegrate. The twist which is applied must only be sufficiently greatfor the fibre assembly to be held together for the winding up and laterunwinding and the transport of the bobbins, in order to avoid inparticular wrong draftings (thin places in the roving yarn). On theother hand, the twist must be easy to be released again, and the rovingmust be capable of being drawn, in order for the subsequent spinningprocess, e.g. in a ring-spinning machine, to be put into effect.

As a slubbing machine, usually a so called speed frame is used, whichmanufactures the correspondingly-named flyer slubbing. This slubbingmachine is equipped with a drafting device and a spindle for winding upthe flyer slubbing onto a cylinder bobbin by means of a flyer to supportthe slubbing against the centrifugal force incurred by the bobbinrevolutions. The speed frame is an expensive machine in the spinningprocess as a whole, due to the complicated winding mechanism. Added tothis is the fact that the usual output from a speed frame is about 20-25metres of roving yarn per minute. This low production cannot beincreased in view of the winding system with flyers, since a higherspeed is limited by the centrifugal force which the flyers and rovingbobbin must withstand.

Accordingly, attempts have already been made by what is referred to asdirect spinning to circumvent the slubbing machine, with which thesupply material for the ring-spinning machine consists of a sliver. Thehigh draft produced by what is referred to as sliver direct spinningonly achieves the result to a restricted degree which is obtained withthe supply of a flyer slubbing on the ring spinning machine. Thisapplies in particular if fine yarns with Nm 50 and finer are being spun.In addition, the supply of drafting cans with ring-spinning machines iselaborate and complicated.

One possibility for replacing a speed frame is disclosed in the printedspecification EP 375 242 A2 This describes a machine for the manufactureof a roving yarn from a fibre assembly which has a twist applicationmeans with a rotating rotor. The rotor exhibits a continuouslongitudinal hole on its axis of rotation, through which the fibreassembly which is to be rotated is guided. The rotor has at a specificheight several holes rotationally symmetrically arranged in the radialdirection. These radial holes connect the longitudinal hole, throughwhich the fibre assembly is guided, with the outer surface of the rotor.This outer surface of the rotor is subjected to a vacuum or a strongunder-pressure. If the fibre assembly is now drawn through thelongitudinal hole, individual free fibre ends are sucked off the surfaceof the fibre assembly into these radial holes. In operation, the rotorrotates while the fibre assembly is drawn through the longitudinal hole.The fibre ends located in the radial holes are in this way wound aroundthe moving fibre assembly, as a result of which a rotation (true twist)is applied to the fibre assembly or its individual fibres.

The device according to the step described is relatively expensive inmanufacture and operation due to the mechanical elements (rotatingrotor) and the vacuum technology.

For the manufacture of yarns the principle is known, for example from DE32 37 989 C2, of drawing a fibre slubbing or drawing sliver in adrafting device and then applying a twist to the drawn fibre assembly,whereby the application of the twist is effected by air jets in twosequential twist chambers. The application of the twist in the firstpneumatic twist chamber is effected in counter-direction to the furtherfollowing twist application in the second pneumatic twist chamber (thefirst twist application causes, for example, a left-hand rotation, whilethe following twist application in the second twist chamber causes aright-hand rotation). In this way a yarn is produced in accordance withwhat is known as the false twist spinning process).

According to Patent Specification CH 617 465, a false twist nozzle isused for the manufacture of a staple fibre yarn (likewise a false twistspinning process).

During the production of a yarn, i.e. during a spinning process, theindividual fibres are spun or twisted together to the extent that thetwisting is irreversible, and the yarn produced also cannot be drawn anyfurther. The strengthening achieved by the twisting is also necessaryfor the yarn, since only in this way it will obtain the necessary hightensile strength. The consequence of this, however, is that the devicesand spinning processes referred to are not suitable for forming a rovingyarn. The roving yarn exhibits only what is referred to as a protectivetwist, which must not impede the further spinning processes on thefollowing machines (e.g. drafting at the ring-spinning machines); i.e.the roving yarn must remain capable of being drawn or drafted. Thedevices described in these two publications are therefore only suitablefor the manufacture of yarns and not of roving yarn capable of beingdrafted.

The object of the present invention is to provide a slubbing machine anda method for the manufacture of a roving yarn, with which thedisadvantages referred to heretofore of conventional slubbing machinescan be avoided, and with which a roving yarn is manufactured thatexhibits the characteristics of conventional flyer slubbings or rovingyarns respectively, with regard in particular to the drafting capabilityof the roving yarn which is manufactured.

This object is resolved by the features in the independent claims 1, 2,10, 14 and 18. By making use of a slubbing machine with twistapplication means according to the invention it is possible for thedisadvantages of the prior art to be circumvented, i.e. in particular toprovide a slubbing machine with a higher production capacity.

Advantageous embodiments and designs of the invention are to be found inthe sub-claims.

The invention, the idea of the invention, and the means of effect of theinvention are explained hereinafter on the basis of embodimentsrepresented in figures. Attention should expressly be drawn to the fact,however, that the invention and the idea of the invention are notrestricted to the embodiments shown in the examples.

FIG. 1 shows in diagrammatic form a spinning position 1 of a slubbingmachine (entire slubbing machine not shown) according to the invention.This possible embodiment of the invention exhibits a drafting device 2(likewise represented diagrammatically), which is supplied with a fibreassembly 3 (e.g. a doubled sliver). The (drafted) fibre assembly 3passes from the drafting device into the twist application means 4. Inthe twist application means 4 the fibre assembly 3 is twisted to form aroving yarn 9, i.e. the fibre assembly is at least partially subjectedto a true twist (i.e. at least a part of the fibres of the fibreassembly). In addition to this, FIG. 1 shows a pair of delivery rollers8 with a nip line 34 and a winding device 7 (likewise representeddiagrammatically) for the roving yarn 9. The device according to theinvention does not necessarily need to show a drafting device 2, as isrepresented in FIG. 1, and still less a pair of delivery rollers 8. Inaddition to the drafting device 2, or instead of the drafting device 2,a conventional drawing frame (not shown) can be provided inside the samemachine (hereinafter referred to as “combination”). Such a drawingframe-slubbing machine combination shows the advantage of a shorteningat the process.

The twist application means 4 operate according to what is referred toas the Vortex process, a special air-spinning method. The Vortexair-spinning method is inherently known as a yarn spinning process. Asalready described heretofore, devices for the forming of yarn areinherently unsuitable for the manufacture of a roving yarn capable ofbeing drafted. Surprisingly and unexpectedly, experiments with suitablymodified air-spinning devices have revealed that certain air-spinningmethods are also suitable for the manufacture of roving yarns. Toachieve this, however, the dimensions and flow circumstances ofconventional yarn air-spinning devices must be adapted. The twistapplication means according to the invention need only to apply aprotective twist to the fibre assembly in order for the slubbing orroving yarn thereby formed to remain capable of being drafted.Conventional air-spinning devices rotate the fibre assembly in such away that a yarn or thread is formed, which is strongly twisted in such away that the twist is irreversible, and, in particular, is no longercapable of being drafted. By providing correspondingly larger dimensionsfor the air-spinning devices, as well as an adjustment of the flowcharacteristics, and in particular by suitably high delivery speeds, itis possible, to manufacture roving yarns or slubbings capable of beingdrafted with air-spinning devices. The appropriate characteristics canbest be determined experimentally. According to initial experiments,air-spinning devices for roving yarns show for preferentially one ormore of the following properties:

-   -   For preference, the diameter of the twist or swirl chamber        amounts to at least 5 mm (see swirl chamber 5 in the Figures        described hereinafter)    -   For preference, the delivery speed of the fibre assembly (from        the delivery rollers of the drafting device) amounts to at least        200 m/min    -   For preference, the pressure of the air flow, before it flows        through the nozzle holes or nozzles into the swirl chamber,        amounts to a maximum of 5 bar (see air flow 32, 16, 16.1, 16.2,        or 20, as well as nozzle holes or nozzles 11 in the Figures        described hereinafter)    -   For preference these air-spinning devices administer a deep        wrapping rotation to the roving or slubbing respectively, and        for preference the wrapping rotation and the coefficient of        rotation respectively alpha_(m) is less than 100.

The mode of action of the device, according to the invention, for theformation of a roving yarn is similar to that of conventionalair-spinning methods for the formation of yarn. For this reason,air-spinning methods are not considered here in any great detail. Bycontrast with conventional air-spinning devices, with the devices andmethods according to the invention, only a protective twist is appliedto the fibre assembly. This protective twist is of such a nature thatthe roving yarn remains capable of being drafted for the furtherprocessing and the application of the twist can even be reversed. It isor would therefore be reversible in contrast to the twist to which afibre assembly would be subjected with conventional, i.e. knownair-spinning devices. To form the roving yarn the fibre assembly issubjected at least in part to a true twist, i.e. at least a part of thefibres of the fibre assembly, if not all, receive a true twist(rotation) by means of an air flow. This true twist or rotationrespectively is, as mentioned, only a protective twist. The roving orslubbing manufactured according to the invention therefore has the sameproperties as a slubbing manufactured with a conventional speed frame.

The remarks just made naturally also apply to all twist applicationmeans, according to the invention of this application, which areillustrated and explained hereinafter on the basis of further figures.These remarks accordingly apply not only to the twist application means4 from FIG. 1, but also to those twist application means with thereference members 15, 17, 18, and 31.

One of the possible twist application means according to the inventionfor the formation of roving yarn is the object 4 from FIG. 1 alreadymentioned. The twist application means 4 operates, as already mentioned,according to what is known as the Vortex air-spinning method. The device4 exhibits for this purpose a fibre guide element 10, with which thefibre assembly 3 is delivered into the swirl chamber 5 of the twistapplication means 4. In the swirl chamber 5 a fluid device, notrepresented in greater detail, creates an air flow 32 or a swirl flowrespectively, by means of one or more nozzle holes 11. Thus resultingswirl flow inside the swirl chamber 5 causes the individual free fibreends 12 to lie on the surface of the fibre assembly 3 around the inletaperture 13 of the roving yarn formation element 6, and, taken up by therotating swirl flow in the swirl chamber, to rotate around the core 14of the fibre assembly. As a result, the fibre assembly 3 in the swirlchamber 5 is subjected at least partially (i.e. to at least a part ofthe fibres) to a true twist by means of an air flow 32. This air flowaccordingly causes at least a part of the fibre assembly, i.e.individual fibres, to be subjected to a true twist about a core offibres remaining largely parallel. The roving yarn 9 which is formed atthe inlet aperture 13 is drawn off, for example, by a pair of deliveryrollers 8 and wound up onto a winding device 7. To do this, the rovingyarn formation element 6 exhibits a hole (see FIG. 1). The windingdevice 7 in FIG. 1 is represented in diagrammatic form only. Forexample, the winding device can be a cross winder, a precisioncross-winder, a random cross-winder, a stepped cross-winder, or aparallel winder.

FIG. 2 shows the twist application means 4 from FIG. 1 in another view.In this illustration it can be particularly readily seen how the fibreassembly 3 is guided by the fibre guide element 10 into the swirlchamber 5, where a swirl air flow, created by the nozzle holes 11, takesup the free fibre ends 12 of the fibre assembly 3 and lays them aroundthe inlet aperture 13 of the roving yarn formation element 6. The freefibre ends 12 lying around the inlet aperture 13 form a “sun” rotatingaround the core 14 of the fibre assembly. The free fibre ends 12accordingly twist about the core 14 of the fibre assembly, as a resultof which the fibre assembly 3 receives at least in part a true twist(rotation) in the swirl chamber 5 as a result of the air flow. Theroving yarn 9 which is formed as a result at the inlet aperture 13 isdelivered (see arrow) by the roving yarn formation element 6 (e.g. aspindle, as represented here).

FIG. 3 shows a further twist application means 15 according to theinvention, although this does not exhibit a roving yarn formationelement. The twist application means 15 (represented diagrammatically)likewise exhibits a swirl chamber 5, in which an air flow 16 (swirlflow) is created by means of one or more nozzle openings 11. By means ofthis air flow 16 the fibre assembly is subjected at least partially to atrue twist in the swirl chamber 5.

The true twist application (true twist in the fibre assembly) isrepresented in FIG. 3a: inside the swirl chamber 5 a rotation is appliedto the fibre assembly by the air flow 16, i.e. at least a part of thefibres of the fibre assembly 3 are rotated, so that the roving yarn 9 isformed.

FIG. 3b shows a variant of the twist application means according to FIG.3a. The twist application means 17 exhibit two swirl chambers 5, whichin each case do not exhibit a roving yarn formation element. The truetwist is applied in this case too by means of one, or in this case two,air flows 16.1 and 16.2. At least a part of the fibres of the fibreassembly 3 receive a true twist (rotation). In this case too, the rovingyarn 9 and the slubbing respectively are delivered and wound up by adevice which is not represented. For preference, the twist applicationmeans 17 exhibit several nozzle holes 11. The nozzle holes 11 serve togenerate the air flows 16.1 and 16.2. The nozzle holes are aligned insuch a way that the emerging air jets jointly and together create ineach case the air flow 16.1 and 16.2 respectively. For this purpose theinlet angles of the nozzle holes 11 are for preference the same insidethe individual swirl chamber 5. The air flows 16.1 and 16.2 are alsodirected in the same way, i.e. such that the two air flows 16.1 and16.2, despite separate swirl chambers, have the same direction ofrotation (right or left rotating air flow).

Overall, for preference in all the embodiments of the inventionattention is paid to the nozzles or nozzle apertures 11 being aligned insuch a way that the emerging air jets are in the same direction, so asto create one parallel air flow with one direction of rotation. Forpreference the individual nozzles or nozzle holes are arranged rotationsymmetric to one another.

For preference the twist application means according to the inventionalso exhibit one or more twist stop elements. Twist stop elements canexhibit different forms; a twist stop element can be formed, forexample, as an edge, a pin, a toroidal surface, a cone, or in the formof several deflecting means.

FIG. 4 shows a twist application means 18 with a twist stop element inthe form of a pin 19. The remaining elements in FIG. 4 correspondlargely to the embodiments already described and also exhibitaccordingly the same reference numbers. The pin 19 in FIG. 4 serves as atwist stop element as well as a false yarn core. Twist stop elementsserve to prevent a twist in the fibre assembly being propagated furtherrearwards. In particular, this prevents any possible false twistoccurring, and therefore prevents any true twist being applied to thefibre assembly. The use of twist stop elements, for the devices andmethod according to the invention is not absolutely necessary, but it isrecommendable. In particular, the true twist application by means of theair flow is improved.

As is shown in FIGS. 4a and 4 b, a pin 19 prevents the twist incurred bythe air flow from propagating further to the rear in the direction ofthe inlet of the fibre guide element in the fibre assembly 3. This canbe seen particularly well in FIGS. 4a, 4 b, and 4 c. The air flow 20around the mouth of the roving yarn formation element (not shown)creates a rotation or a twist respectively inside the fibre assembly 3.Due to the presence of the pin 19 as a twist stop element, the twist ofthe fibres onto the fibre assembly 3 is prevented, which is lying on thefibre guide element 10 and 21 respectively (see parallel non-twistedfibres on the fibre guide elements 10 and 21 respectively in theFigures).

A toroidal fibre guide element 21 can also serve as a twist stopelement. FIG. 4b shows a toroidal fibre guide element 21, whichadditionally exhibits a pin 19. As a result, the twist stop function isparticularly effective. A toroidal fibre guide element 21 with pin isalso represented in FIG. 4c. The elements in FIG. 4c correspond largelyto the elements in FIG. 4b, with the difference that the pin 19 in FIG.4c is truncated.

FIG. 5 shows a fibre guide element 10 with what is referred to as atwist stop cone 24. The twist stop cone 24 fulfils the function of thetwist stop element. The mode of acrion is the same as with the pin 19:cone or pin also serve as what is referred to as false yarn cores. Thefibres or fibre assembly respectively in spiral fashion around the falseyarn core, as a result of which the propagation of the twist against thedelivery direction of the roving yarn or fibre assembly respectively isprevented.

It is also possible for only one toroidal fibre guide element 22 withoutpin to serve as a twist stop element. This is represented, for example,in FIG. 6 (compare with FIG. 4c) A toroidal fibre guide element isinherently sufficient as a twist stop element. The additional use of apin is not absolutely necessary. Different views of a toroidal fibreguide element without pin 22 are shown in FIGS. 6a and 6 b. It is alsopossible for only an edge 33 to serve as a twist stop element, whichdoes not necessarily have to project from a toroidal fibre guideelement.

FIG. 7 shows further twist stop elements which could be used in thedevice according to the invention. The Figure shows a fibre guideelement 23 with several deflection means. These deflection means 26 havethe function, in addition to deflecting the fibre assembly 3, of alsoacting as a twist stop. It can be readily seen in the Figure how thedeflection means 26 take effect with a twist stop function. The fibreassembly is drawn in the non-twisted state in the direction of theroving yarn formation element 6. At the mouth of the roving yarnformation element 6 the free fibre ends 12 are twisted by the air flow20 of the swirl chamber by means of true twist application. The twist ofthe free fibre ends 12 causes a torsion moment, which tries to propagateagainst the delivery direction (arrow) of the roving yarn in the fibreassembly 3. Due to the presence of the deflection means 26 with twiststop function, this torsion moment or twist respectively, which wouldcause the torsion moment in the fibre assembly, is dammed or stopped.This means that no twist propagates into the fibre assembly 3 (seerepresentation respectively in FIG. 7; the fibre assembly is nottwisted). In this way a true twist (rotation) is applied to the fibreassembly 3 by means of the air flow 20, as a result of which the rovingyarn 9 comes into being.

Without the deflection means 26 with twist stop function, the twistwould propagate into the fibre assembly 3, as a result of which what isreferred to as a false twist would occur, which under certaincircumstances prevents a true twist of the fibre assembly or the rovingyarn respectively. A further representation of the circumstances justexplained can be seen in FIG. 7a: Here too it can readily be seen howthe fibre assembly 3 remains untwisted thanks to the deflection means26.

FIGS. 8a and 8 b show deflection means with twist stop function ofdifferent forms. FIG. 8c shows a view of the deflection means 27 and 28respectively in the delivery direction of the roving yarn or the fibreassembly respectively. Different forms for the deflection means withtwist stop function can be conceived. The deflection means 26, 27 and 28shown represent only some of the possible forms.

The slubbing machine according to the invention can for preference alsoexhibit means which determine the width of the fibre assembly beforerunning into the twist application means. These means may be, forexample, funnels or other forms of condensers. Such a means 29 is shownin FIG. 9. The Figure shows a funnel 29 which restricts a fibre assembly3 in its width and leads it to a twist application means 31. Such afunnel 29 or other condenser can be arranged for example downstream of apair of delivery rollers 30. The pair of delivery rollers 30 is shown ina plan view. The reference number 34 indicates the nip line of the pairof delivery rollers 30.

As described heretofore with regard to the embodiments, the slubbingmachine according to the invention, in particular a speed frame,exhibits a special twist application means for the manufacture of aroving yarn from a fibre assembly. The special twist application meansof the slubbing machine according to the invention twists a fibreassembly to form a roving yarn. For this purpose the twist applicationmeans according to the invention exhibit a swirl chamber with a rovingyarn formation element contained within it. For preference the rovingyarn formation element is a spindle. According to the invention, in theswirl chamber of the twist application means a true twist (rotation) isapplied to the fibre assembly at least partially (i.e. to at least apart of the fibres) by means of an air flow.

The slubbing machine according to the invention, for the manufacture ofa roving yarn from a fibre assembly can also exhibit another embodimentof a twist application means: A further twist application means,likewise according to the invention, exhibits a swirl chamber withoutroving yarn formation element (e.g. spindle). This swirl chamberexhibits means, however, which allow for an air flow to come into beingin the swirl chamber. This air flow applies a true twist (rotation) atleast in part to the fibre assembly (i.e. to at least a part of thefibres). This second embodiment of a twist application means accordingto the invention may also exhibit several swirl chambers withcorrespondingly several means for the formation of an air flow (see, forexample, FIG. 3b).

A drafting device can in each case be arranged upstream of the slubbingmachine according to the invention and the twist application meansaccording to the invention.

For preference, the twist application means according to the inventionhave in each case one or more twist stop elements. These twist stopelements can be designed, for example, as edges, pins, as toroidalsurfaces, cones, or as several deflection means. The twist applicationmeans according to the invention can also exhibit a combination of thetwist stop elements just referred to, such as a toroidal surface with apin, or a cone with a pin, or an edge with a pin, or a toroidal surfacewith a pin. The twist application means according to the invention canexhibit several of these twist stop elements or a combination of them.

For preference, the twist application means according to the inventionexhibit several nozzles for the production of the air flow, whereby thenozzles are aligned in such a way that the air jets emerging from themare arranged in the same direction in order to create together an airflow in the same direction. This applies in particular in situations inwhich several swirl chambers are present, i.e. the air flows or swirlair flows have the same twist or flow directions respectively. Forpreference, the nozzle holes are therefore arrangedrotationally-symmetric around the axes of the swirl chambers, or, insituations in which several swirl chambers are present, are arrangedboth rotationally-symmetric as well as rotationally-symmetric-offset onan axis (the entry angles of the nozzle holes are therefore the same).If several swirl chambers are present, the nozzles can for preference bearranged in such a way that the nozzles of an individual swirl chamberare indeed arranged rotationally-symmetric, but each swirl chamberexhibits a different entry angle for the individual nozzles. The airjets emerging in the individual swirl chambers do indeed remain directedin the same direction, in the sense of a left or right rotation, buthave different “lead angles”. Even if the swirl air flow arising indifferent swirl chambers exhibit different “lead angles”, the twistwhich is applied nevertheless remains in the same direction, i.e. thefibre assembly or roving yarn respectively undergoes a left or righttwist in all the swirl chambers. A rotation-symmetric arrangement of thenozzles is shown, for example, in FIG. 2. A rotation-symmetric offsetarrangement of the nozzles can be seen in FIG. 3b (the nozzle holes 11of the two swirl chambers are, by analogy with FIG. 2, also arrangedrotationally-symmetric).

For preference, the slubbing machines and twist application meansaccording to the invention exhibit a means, in particular a funnel or anaerodynamic or mechanical condenser, which has the function ofdetermining the width of the fibre assembly before it runs into thetwist application means.

For preference, the distance interval between the intake aperture of theroving yarn formation element (e.g. spindle) and the last nip line (e.g.of the pair of delivery rollers) is not greater than the longest fibrelength obtained in the fibre assembly or greater than the medium staplefibre length of the fibre assembly.

For preference, the distance interval between the inlet of the twistapplication means and the last nip line (e.g. of the pair of deliveryrollers of a drafting device) is not greater than the longest fibrelength obtained in the fibre assembly.

For preference, a winding device is allocated to the slubbing machineaccording to the invention. This winds up the roving yarn emerging fromthe twist application means. For preference, the winding device is across-winder, a precision cross-winder, a random cross-winder, a stepprecision cross-winder, or a parallel winder.

For preference, the yarn formation element is a spindle.

The invention also includes the inventive use of a twist applicationmeans, which operates in accordance with any air-spinning method andserves to manufacture a roving yarn, whereby the twist application meansexhibits only one swirl chamber with a roving yarn formation element(e.g. spindle) contained within, and where the fibre assembly issubjected in the one swirl chamber at least partially (i.e. to at leasta part of the fibres) to a true twist (rotation) by means of an air orair swirl flow.

With the use of a twist application means according to the invention,for preference a parallel air flow is created in the twist applicationmeans in the meaning of the foregoing explanations (i.e. all air flowsin the twist application means are either left or right rotating, inorder to produce a corresponding twist going either left or right).

With the use of a twist application means according to the invention,the twist application means exhibits for preference one, two, three,four, five, six, or more nozzles for producing the air flow. Forpreference, these nozzles are arranged rotationally-symmetric orrotationally-symmetric-offset (see explanations above regarding this,and compare with FIGS. 2 and 3 b).

For preference, a twist application means which can be used according tothe invention exhibits several nozzles for the production of an airflow, which are aligned in such a way that the emerging air flows areparallel and together produce one parallel air flow (in accordance withthe previous explanations, air flows rotating left or right). In orderfor the emerging air flows to be parallel in a swirl chamber, they arefor preference arranged rotationally-symmetric around the axis of theswirl chamber or around one axis in the swirl chamber.

The invention also includes a method for the manufacture of a rovingyarn from a fibre assembly according to the invention. With this methodaccording to the invention, the fibre assembly is first drafted (e.g. ina drafting device) and then at least partially (i.e. at least a part ofthe fibres of the fibre assembly) subjected to a twist application(rotation). This twist application is a true twist application and isproduced by means of a single air flow in a single swirl chamber.

For this method according to the invention, for preference severalnozzles are present for the production of the air flow. For thispurpose, the nozzles are for preference arranged in such a way that theemerging air jets are parallel, in order to produce together oneparallel air flow. For this purpose the nozzles are for preferencearranged rotationally-symmetric around one axis orrationally-symmetric-offset around one axis (see explanations above andFIGS. 2 and 3b).

With the slubbing machine according to the invention as discussedheretofore, in particular speed frame, with the use according to theinvention of a twist application means or with the method according tothe invention for the manufacture of a roving yarn, only a protectivetwist is applied; i.e. the roving yarn produced by the air flow iscapable of being drafted. The twist (rotation) could be removed againfor the further processing of the roving yarn, e.g. to a ring-spun yarn.

All slubbing machines according to the invention as described, theirtwist application means, and all uses according to the invention asdescribed of twist application means, or the method according to theinvention for the manufacture of a roving yarn, operate for preferencenot in accordance with a false twist method.

The invention also includes a drawing frame-slubbing machinecombination. This combination or machine respectively exhibits aconventional drafting frame for doubling and drafting several fibreassemblys, arranged downstream of which is slubbing machine according tothe invention, in accordance with the foregoing explanations andembodiment examples, inside the same machine. This likewise inventivemachine accordingly represents a new machine unit, which combines initself a draw frame and a downstream slubbing machine, in accordancewith the explanations given above.

The invention is not restricted to the explicitly cited possibilitiesand embodiments. Rather, these variants are intended to be incentivesfor the person skilled in the art to implement the idea of the inventionin as favourable a manner as possible. Accordingly, further advantageousembodiments and combinations can be easily derived from the embodimentsdescribed and shown in the Figures, which likewise reproduce the idea ofthe invention and should be protected by this application. Some of thedisclosed features of the invention have been described as combined inthis description, and will be claimed as combined in the followingclaims. It is also conceivable, however, for individual features of theinvention to be claimed alone or in another combination in applicationof the idea of the invention. The applicants therefore expressly reservethe right to make provision for other combinations in the use of theidea of the invention.

1. Slubbing machine for the manufacture of a roving yarn (9) from afibre assembly (3), preferably a speed frame, containing one or morespinning positions (1) having each a twist application means (4) andpreferably a drafting device (2) arranged upstream of the twistapplication means (4), characterized in that the twist application means(4) contains a swirl chamber (5) with a roving yarn formation element(6) contained within it, whereby the fibre assembly (3) is subjected inthe swirl chamber (5) to a true twist, or at least in part to a truetwist, by means of an air flow (32). 2-18. (canceled)